1. Field of the Invention
The present invention relates to a system and a method for restricting the communication using a mobile terminal represented by a mobile telephone and a PHS (personal handy phone system) terminal.
2. Description of the Related Art
When a mobile communications system such as a car phone system, a mobile telephone system, etc. has first introduced, enormous efforts have been expended for extending the communication range (service area) for mobile terminal users. To enlarge the service area, it has been necessary to install a large number of radio base stations (access points) for communications with mobile terminals in a wider communication range. To attain the purpose, the initial development of the mobile communications system when it was introduced was to produce an apparatus for constituting the radio base station at a lower cost.
Then, the service area has been enlarged, the convenience of the mobile communications system has been widely recognized, and the number of mobile terminal user has sharply increased. As a result, the communication traffic increased, and the insufficient communication capacity has become the problem to be solved. To solve the problem, the number of communication channel to be used for the mobile communications had to be extended, that is, the “communication traffic per unit area” had to be extended. To realize this, a transmission system with high communication efficiency, a high-performance coding system in a voice transmission service, a dynamic channel assignment system for dynamically arranging communication channels for realizing the communication density depending on the geographical/timing factor, etc. have been developed.
Furthermore, variations of new applications have demanded providing various types of services, that is, multimedia services including conventional telephone services and distributing services of text, images, etc.
Thus, in the mobile communications system, to allow a larger number of users to enjoy communication services, it has been necessary to deal with a wide distribution of time-varying user mobile terminals with high density.
However, contrary to the technical tendency to require high communication capability, there is a request to suppress the communication capability. That is, there is a request to restrict communication by mobile terminals in a specific area. There is the possibility that the communication using a mobile telephone, etc. can be nuisance to people around, and the related trouble has increased these days.
Actually, in the communication using a mobile telephone, the telephone conversation can be nuisance to the people around. Furthermore, the ringing sound (beep, electronic sound, melody, etc.) activated when a call is terminated might surprise the people around, which considered to be nuisance. From the point of view that such nuisance has to be suppressed, there are places where a notice or a warning to inhibit the communication using a mobile terminal. However, some users ignore the notice or warning and continue the telephone conversation using their mobile terminals. In addition, since a piece of advice by a person nearby to such a mobile terminal user to stop using the mobile terminal could cause trouble, the use of the mobile terminal is normally overlooked as is. The situation occurs in the places where silence is demanded such as a public transportation, for example, a train, a bus, etc., a concert hall, a lecture hall, a conference room, etc.
It is also pointed out that there may be the possibility of undesired influence of an electromagnetic wave emitted from a mobile terminal on an electronic equipment device, for example, a heart pacemaker, a hearing aid, a medical equipment, etc. For example, there is the case where the electromagnetic wave energy from a mobile terminal causes a malfunction of the clock mechanism of an electronic equipment device and a data processing mechanism, resulting in an incompetent electronic equipment device. Thus, the heart pacemaker, etc. can cause a serious crisis to a life. Thus, in a place where there is a person having a heart pacemaker implanted or having a hearing aid applied, or in a hospital wing or an operation room where medical equipment is installed, it is requested that the use of a mobile terminal is strictly restricted.
The above-mentioned restriction refers to an example of an unconditional restriction of the services to a user. Aside from this, under the conditions of places and timing, services for users can be selectively restricted. For example, there can be selective restriction depending on the positions in a train by, for example, prohibiting the power-on of a mobile terminal around the priority seats, and prohibiting the ringing sound and voice conversation using a mobile terminal but permitting the communication service not making noise such as transmission and reception of e-mail at the other places in the train. There is also a case there are selective restrictions depending on the situation of the places by, for example, stopping services in the time of a crowd, etc. when people are close to one another, and permitting the services in no-crowd time.
Furthermore, a mobile terminal has the function of so-called “location registration” to report the location of the user terminal to the mobile communication network. Since the function is constantly operated, the mobile terminal constantly radiates radio wave even in the waiting state. The radiated radio wave also has an influence on the medical equipment nearby.
As described above, for the communication services to the mobile terminal users, there are the places and time to be restricted depending on the circumstances, and an appropriate method for realizing the communication service restriction in the places and time is demanded. To meet the demand, there are a number of methods adopted.
As a method of restricting the communication service depending on the circumstances of the user, there is a method of disabling the communication of the mobile terminal in the communication area by the technical mechanism in addition to the method of notifying mobile terminal users that voice communication is prohibited by putting up a notice or broadcasting by voice. The method can be roughly classified into (1) a method of cutting off an extraneous radio wave for the mobile communications from the outside area and disabling the communication function of a mobile terminal itself in the area (first method), (2) a method of providing an interference wave for a radio frequency used by mobile terminals and making the communication function of a mobile terminal not to work properly in the area (second method), (3) a method of notifying mobile terminals by transmitting a signal for suppressing the communication at a radio frequency different from the radio frequency used by the mobile terminals (third method), (4) a method of suppressing the communication in the location area of the mobile terminal by recognizing the location area (fourth method), and (5) other methods.
The first method is a method for physically setting a wall material, etc. for cutting off a radio wave for the mobile communications such that the entire space where mobile terminals exist should be covered, and disabling the communication function of a mobile terminal itself in the area. FIG. 30 shows an example of the first method. By referring to FIG. 30, the space of area 1801 in which the communication is to be restricted is covered with a wall material 1701 for cutting off a radio wave for the mobile communications. Mobile terminals 201 and 202 in the area 1801 are service-restricted, and the mobile terminal 203 outside the area 1801 is not service-restricted. A radio base station having a communication area for covering the area 1801 is installed at a place not shown in the drawing.
In the first method, the cost for setting the wall material 1701, etc. for cutting off a radio wave for the mobile communications is required. In addition, it is necessary to remove the wall material 1701 if the area 1801 is to back to normal area in which the communication can be allowed after setting the wall material 1701. Therefore, it is difficult to apply this method to the place such as a concert hall, etc. where communication restriction is released after an event is over.
It is also difficult to apply this method to a train, etc. Applying a radio wave cutoff material or a radio wave absorber to a train causes passengers to feel confined visually and in ventilation. When a window of the train is open, the radio wave cutoff state cannot be maintained.
As described above, the place where the first method is applied is limited to a place where communications are constantly prohibited, a place where the presence of the radio wave cutoff material is not annoying, a place where the radio wave cutoff material setting cost is acceptable, etc.
The second method is to providing a noise radio signal and making the communication function of a mobile terminal not to work properly in the area, and expecting the use of a mobile terminal is abandoned. FIGS. 31A and 31B show examples of the second method. In FIG. 31A, a noise radio signal source 351 is provided in an area 1810 in which services are restricted. The size of the area 1801, where the services are practically restricted, depends on the intensity of the noise radio signal from the noise radio signal source 351. The communication of the mobile terminal 201 in the area 1801 is prevented by the noise radio signal from the noise radio signal source 351, and the services are practically restricted. Since the communication of the mobile terminal 202 outside the area 1801 is not prevented by the noise radio signal from the noise radio signal source 351, the services are not restricted.
In the second method, since it is necessary to provide power supply equipment for constantly supplying electric power to the noise radio signal source 351 for generating a noise radio signal in addition to the noise radio signal source 351 itself, the method is costly.
There is a method of a radio base station coverage area control system described in the patent document 1 (Japanese Patent Application Laid-open No. H5-167511). This system is similar to the second method for preventing the communication service by generating noisy radio signals using the same frequency as the mobile terminals in the coverage area of the mobile communications system. According to the system, since the noise radio signal can be generated/stopped for activating/releasing the service restriction, it is more advantageous than the first method in that the communication status can be controlled in terms of time. However, since it is difficult to design the range reached by the noise radio signal radiated from the noise radio signal source in a geographically precise shape, it is difficult to strictly provide the area for restricting the communication of a mobile terminal. The area 1801, in which the communication of a mobile terminal is to be restricted by the noise radio signal, forms spherical shape or ellipsoidal shape. For example, as shown in FIG. 31A, when the shape of the area 1810, in which the communications of mobile terminals are to be restricted, is box-shaped, and if the area 1801 is set to be stored in the area 1810, services for mobile terminals cannot be restricted at the corners of the area 1810. On the other hand, as shown in FIG. 31B, when an area 1802 is made larger than the area 1810, and services for mobile terminals can be restricted at the corners of the area 1810, communications are restricted also on the mobile terminal 251 outside the area 1810.
As the methods for solving the above-mentioned problems, there are a method of using plural noise radio signal sources of noise radio signal having a short distance reached and a method of providing the radiation pattern of the antenna of the noise radio signal source in the shape of the area 1810. Since the former uses plural noise radio signal sources, the cost increases. Since the latter also requires a high-performance and costly equipment using the antenna radiation technology (for example, adaptive array antenna) of varying the antenna radiation pattern, it is not practical and lacks the flexibility in changing an arrangement.
The third method is different from the method of generating noise radio signal in the view point of a radio frequency which is different from the radio frequency used in the communication by mobile terminals, and is also different from the second method in the view point of a nature of signal which is a notice signal to be broadcasted to mobile terminals. As the third method, there is disclosures of a ringing sound control method of the radio mobile communication terminal, a radio mobile communication terminal, and a radio mobile communications system described in the patent document 2 (Japanese Patent Application Laid-open No. H11-215561), and a mobile radio equipment, a mobile communications system, and a communication restriction control method for the mobile radio equipment described in the patent document 3 (Japanese Patent Application Laid-open No. H11-215562). A service restriction control base station replaces the noise radio signal source 351 shown in FIGS. 31A and 31B. Services are restricted by mobile terminals receiving a signal of a notice of service restriction from the service restriction control base station.
Also in the third method, as in the case of the second method, it is difficult to have the same shapes between the area 1801 and the area 1810. Therefore, as explained above-mentioned by referring to the second method, services could not be restricted at the corners of the area 1810, or a mobile terminal outside the area 1810 could be service-restricted depending on the size of the area 1801. It may be possible to solve the problem by forming the shape of the area 1801 to be close to the shape of the area 1801 by changing the distance reached by a notice signal from the service restriction control base station. However, in this case, there is the problem similar to the problem explained in the second method.
The fourth method is a method of recognizing the area in which mobile terminals are located and discriminating whether or not communications are to be suppressed in the area. One of the discriminating methods is to obtain the position coordinates information about the location of mobile terminal by a positioning system, etc. and determine the necessity to suppress services according to the position coordinates information. This method is disclosed by, for example, a use restriction method of mobile station and a mobile communications system described in the patent document 4 (Japanese Patent Application Laid-open No. 2001-136564). Another method is to provide a mechanism of detecting by an additional sensor whether or not a mobile terminal has entered a communication suppressed area or whether or not a mobile terminal has exited the communication suppressed area, and perform the communication suppressing process by grasping whether or not there is a mobile terminal in the communication suppressed area. This method is disclosed by a mobile telephone communication suppression equipment and the method described in the patent document 5 (Japanese Patent Application Laid-open No. 2002-271850).
In the case of the method disclosed by the patent document 4, it is necessary to mount the positioning system into a mobile terminal. Therefore, the mobile terminal becomes large and costly. When a positioning system uses a communication satellite such as a GPS (global positioning system), etc., a larger mechanism is required, and the system is disadvantageous in mobility. In addition, there occurs the problem that the method cannot be used in the place (in a building, an underground space, etc,) where radio signals from the communication satellite cannot be received.
In the case of the method disclosed by the patent document 5, it is necessary to correctly recognize the entry and the exit of the mobile terminal in an entrance area. However, when the entry or the exit of the mobile terminal is detected, and then a sensor does not correctly work for any reason (for example, the difference in sensitivity of a sensor depending on the location of the sensor, the entry and the exit through a gate other than the gate where the sensor is placed, the action of cutting off a radio signal from the sensor incidentally or intentionally), the system cannot correctly recognize the entry or the exit of the mobile terminal. In this case, the communication of mobile terminal that has entered a specific area cannot be appropriate restricted, or the communication of mobile terminal that has exited a specific area could be continuously suppressed.
Mainly described above are the methods of suppressing the communication service of mobile terminal. On the other hand, there is also a request to provide a selective restriction of service by not uniquely determining an allowed service depending on the current location of mobile terminal, but prohibiting a certain service and permitting other services selectively. For example, in a train, the voice communication using a mobile terminal is prohibited, but transmission or reception of text data (for example, e-mail, etc.) is permitted. In the situation, a method of notifying a user of a mobile terminal of the information on the notice or by voice announcement is used. However, the restriction by this method largely depends on the personal manner of a user of mobile terminal, and services cannot be restricted on persons of poor manners.
In the above-mentioned cases, when the first method is applied, not only the voice communication but also all other communications of mobile terminals in a train are disabled, and the selective service restriction cannot be performed. The first method can be applied only when all communication services for mobile terminals are disabled.
Similarly, when the second method is applied, not only the voice communication but also all other communications of mobile terminals are disabled, and the selective service restriction cannot be performed. The second method also can be applied only when all communication services for mobile terminals are disabled.
The third method can selectively restrict the services, like A) prohibiting both voice communication and other communications, B) prohibiting only voice communication, or C) permitting all services, etc., depending on the contents of notice signal. However, when a restricted area is provided, the geographical precision cannot be satisfied.
The fourth method can also selectively restrict services by defining a service restriction condition in advance on a region or an area in which mobile terminals are located. However, there is a place where a positioning process cannot be performed, and the current location of mobile terminal cannot be recognized in such a case.
A recent mobile terminal has various functions, and the causes of undesired influences and unpleasantness to the people around are not limited to voice communications or ringing sounds. For example, when music data accumulated in the memory of a mobile terminal is replayed, the reproduced sound can be noisy to the people around. Furthermore, there can be nuisance that a person carrying a mobile terminal having the voice recording mechanism and image recording mechanism (not limited to static images or moving pictures) takes a picture of other persons without permission. These problems are also left to the personal manners of users, and there are no effective countermeasures against the users of poor manners. The main cause of the problems is that the operations of a mobile terminal such as replaying and recording sound and images, etc. are so-called offline operations in which a mobile terminal is operated as disconnected from a communication system, and it is considered that it is not necessary for the communication system to suppress or restrict the operations. However, the nuisance by these functions to the people around has recently been recognized as a serious problem, and there is a request to restrict or suppress the nuisance use in any method.
In addition to the above-mentioned problems, there is another aspect to be solved. It is desired to provide a communication system which can execute or restrict services depending on the current location of a mobile terminal or the surrounding circumstances of a mobile terminal. The conventional methods of restricting the communication of a mobile terminal are to equally restrict the communication services such as voice communication, reception of a call, ringing sound, transmission/reception of e-mail, etc. by an alternative between prohibition and permission for all mobile terminals or a part of mobile terminals in the restricted area. Therefore, it is difficult to perform flexible communication and service restriction depending on the place and circumstances. Practical requests and problems are described below.
The advantage of the communication restriction control of a mobile terminal is to suppress inconvenience and the influence on electronic equipment, but there are various circumstances in which communication restriction control is demanded, and there is a case where communication restriction control is not required depending on the circumstances. For example, it is not necessary to restrict communication of a mobile terminal when there is no person near by who has an implanted biomedical equipment and is affected by electromagnetic wave energy emitted by a mobile terminal. For example, when there is no passenger sitting on the priority seat, the situation occurs.
The energy type of a radio wave emitted by a mobile terminal (the amount of transmission electric power, or continuity/intermittence of radio wave energy radiated for the transmission of a signal) depends on the communication system, and some energy types have a small influence on electronic equipment such as biomedical equipment, etc., and there is a case where no communication restriction control is required. Practically, the influence of electromagnetic wave energy on biomedical equipment can be a damage of equipment itself by the electromagnetic wave energy radiated from a mobile terminal, a malfunction of biomedical equipment for which no sufficient countermeasure is taken against an electromagnetic wave by noise power in a pulse form generated by the intermittent radiation of electromagnetic wave energy. However, the level of the influence depends on the communication system. For example, electronic equipment, which indicates a malfunction by the electromagnetic wave energy (noise power in a pulse form) from a mobile terminal of the TDMA (time division multiple access) system, may not indicate a malfunction by the electromagnetic wave energy of the CDMA (code division multiple access) system.
An influence on electronic equipment also relates to the communication speed with reference to the transfer rate of the transfer information. When the communication speed with reference to the transfer rate of the transfer information is high, the required amount of transmission power increases, and it has a large influence on such electronic equipment. However, when the communication speed with reference to the transfer rate of the transfer information is low, the required amount of transmission power decreases, and it has a small influence. Thus, by reducing the communication speed with reference to the transfer rate of the transfer information, the influence on electronic equipment such as a malfunction, etc. can be suppressed, and it is not necessary to turn off the power supply to a mobile terminal or completely cut off the communication of a mobile terminal.